NAME    [Toc]    [Back]

       glClear - clear buffers to preset values

SYNOPSIS    [Toc]    [Back]

       void glClear(
               GLbitfield mask );

PARAMETERS    [Toc]    [Back]

       Bitwise  OR  of  masks  that  indicate  the  buffers to be
       cleared.   The   four   masks   are   GL_COLOR_BUFFER_BIT,
       GL_DEPTH_BUFFER_BIT,   GL_ACCUM_BUFFER_BIT,  and  GL_STENCIL_BUFFER_BIT.

DESCRIPTION    [Toc]    [Back]

       glClear() sets the bitplane area of the window  to  values
       previously  selected  by  glClearColor(),  glClearIndex(),
       glClearDepth(), glClearStencil(), and glClearAccum(). Multiple
  color  buffers  can  be  cleared  simultaneously by
       selecting more than one buffer at  a  time  using  glDrawBuffer().


       The pixel ownership test, the scissor test, dithering, and
       the buffer writemasks affect the operation  of  glClear().
       The scissor box bounds the cleared region. Alpha function,
       blend function,  logical  operation,  stenciling,  texture
       mapping, and depth-buffering are ignored by glClear().

       glClear()  takes  a single argument that is the bitwise OR
       of  several  values  indicating  which  buffer  is  to  be
       cleared.

       The values are as follows: Indicates the buffers currently
       enabled for color writing.  Indicates  the  depth  buffer.
       Indicates  the accumulation buffer.  Indicates the stencil
       buffer.

       The value to which each buffer is cleared depends  on  the
       setting of the clear value for that buffer.

NOTES    [Toc]    [Back]

       If  a  buffer is not present, then a glClear() directed at
       that buffer has no effect.

ERRORS    [Toc]    [Back]

       GL_INVALID_VALUE is generated if any bit  other  than  the
       four defined bits is set in mask.

       GL_INVALID_OPERATION is generated if glClear() is executed
       between the execution of glBegin() and  the  corresponding
       execution of glEnd().

ASSOCIATED GETS    [Toc]    [Back]

       glGet() with argument GL_ACCUM_CLEAR_VALUE
       glGet() with argument GL_DEPTH_CLEAR_VALUE
       glGet() with argument GL_INDEX_CLEAR_VALUE
       glGet() with argument GL_COLOR_CLEAR_VALUE
       glGet() with argument GL_STENCIL_CLEAR_VALUE

SEE ALSO    [Toc]    [Back]

       glClearAccum(3),     glClearColor(3),     glClearDepth(3),
       glClearIndex(3),    glClearStencil(3),     glColorMask(3),
       glDepthMask(3),  glDrawBuffer(3), glScissor(3), glStencilMask(3)



                                                      glClear(3G)